Catalytic oxidation of halogenated hydrocarbons



Patented Aug. 10, 1948 UNITED STATES PATENT OFFICE CATALYTIC OXIDATIONOF HALOGENATED HYDROCARBONS William E. Vaughan and Frederick F. Rust,Berkeley, Calii'., assignors to Shell Development Company, San Francisof Delaware co, CaliL, a corporation.

No Drawing. Application February 20, 1946, Serial No. 649,115

16 Claims. (Cl. 260-610) as well as the corresponding halogenatedalcohols. The organic hydroperoxides and alcohols produced in accordancewith this invention have the same number of carbon atoms in the moleculeas the starting material.

The oxidation of various hydrocarbons has been effected for a number ofyears both non-catalytically and in the presence of various catalysts.

As a general rule, most, if not all, of these oxi-I dations resulted inconsiderable decomposition of the hydrocarbons, i. e, cleavage ofcarbon-to-carbon bonds of the organic starting material. Also, theproducts of reaction of such oxidations contained various percentages ofhydrocarbons which have been oxidized to a greater or lesser extent. Forinstance, the catalytic oxidation of paraflinic hydrocarbons inaccordance with the action mixtures and the recovery of the individualcompounds therefrom are frequently very dlfli-.

cult, if not commercially impossible, or at least greatly increases thecost of the final product or products.

It is frequently desirable to obtain predominantlycarboxylic acids,organic peroxides (including organic hydro-peroxides), alcohols and/trketones rather than mixtures containing them and large amounts of otheroxygenated compounds, e. g. carbon dioxide, carbon mono x,

lde, aldehydes, lactones, and the like. 'Furthermore, it is usuallyimportant or desirable toobtain such oxygenated compounds having atleast the same number of carbon atoms per molecule as the startingorganic material. In all such cases the known methods of partialoxidation of hydrocarbons, whether they be catalytic or non-catalytic,are impractical because of thepartial orcomplete decomposition of thestarting organic materials to form carbon and compounds containing fewercarbon atoms per molecule, as well as due to the formation of mixturesof compounds which are oxygenated to a greater or lesser degree.

It is a principal object of the present invention to provide a novelprocess enabling halogenated hydrocarbons to be oxidized whereby highyields of predetermined oxygenated organic comteachings of the prior artformed mixtures con-' taining various percentages of carbon monoxide,carbon dioxide, olefins, water, as well as some aldehydes, alcohols,acids, acetals, esters, ketones and other hydrocarbon-oxygen compounds.Similarly, the catalytic oxidation of aromatic hydrocarbons, e. g.toluene, in accordance withthe teachings of the prior art frequentlyformed mixtures containing various percentags of saturated andunsaturated hydrocarbons, saturated and 'un saturated aliphatic andaromatic aldehydes, ketones, lactones, alcohols and other oxygenatedcompounds such as carbon dioxide. Furthermore,

these various oxygenated compounds formed during the oxidation ofvarious hydrocarbons, according to the teachings of the prior art,usually contained varied numbers of carbon atoms per molecule owing toscission of carbon-to-carbon bonds, as well as to other side reactionssuch as polymerization, condensation and the like.

pounds formed as a result of partial oxidations of hydrocarbons aregenerally more valuable than the primary materials subjected to theoxidation reaction, the subsequent fractionations of the r e Althoughmost of the oxygenated organic compounds containing halogen, some ofwhich are.

novel, may be obtained. A further object of the "invention is to providea process for the production of high yields of halogenated organicperoxides and alcohols to the substantial exclusion of other oxygenatedcompounds. A still further object is to provide a process wherebyhalogenated hydrocarbons'containing a tertiary carbon atom of aliphaticcharacter may be oxidized to produce predominantly the correspondinghalogenated alcohols and hydroperoxides having the same number of carbonatoms as the starting material. Another object is to provide a processfor controlled catalytic oxidation of halogenated hydrocarbonscontaining a saturated tertiary carbon atom to produce valuable andnovel halogenated hydrocarbon hydroperoxides. Still other objects willbe apparent from the description of the invention.

' In our copending applications Serial No. 474,224, filed January 30,1943, now US. Patent No. 2,395,523, and Serial Nos. 510,420 and 510,421,filed November 15, 1943, now U. S. PatentNos. 2,403,771 and 2,403,772,ofwhich the present application is a continuation-in-part, we havedescribed the controlled oxidation of hydrocarbons likelsobutane withoxygen in the presence of hydrogen bromide, whereby there are producedorganic peroxides like tertiary-butyl hydroperoxide anddi-tertiary-butyl hydroperoxide. We have now discovered that halogenatedhydrocarbons containing a saturated tertiary carbon atom with one ormore like or different halogen atoms of atomic No. 9 to 35 linked toother carbon atoms than the tertiary carbon atom can be oxidized tovaluable compounds by the partial and controlled oxidation in thepresence oi! added hydrogen bromide as catalyst. In one of its morespecific embodiments the invention resides in the production ofchlorinated or brominated peroxides and hydroperoxides by subjectingchlorinated or brominated hydrocarbons containing a tertiary carbon atomof aliphatic character to the action of oxygen or an oxygen-containingor oxygen-yielding material in the presence of hydrogen bromide, thisoxidation being eil'ected at temperatures and pressures below thosecapable of causing spontaneous combustion and thereby the resultantdecomposition of the structure of the starting halogenated hydrocarbon.

The above outlined invention is predicated on our discovery that thepresence of added hydrogen bromide during the oxidation 01' the definedclass of halogenated hydrocarbons controls the oxidation reactions sothat oxidation occurs predominantly on the carbon atom or atoms to whicha halogen atom would usually attach itself if the starting compound weresubjected to a halogen substitution reaction, 1. e. oxidation will occurupon the tertiary carbon atom having the replaceable hydrogen atomlinked directly thereto. Furthermore, it has been found that thepresence of hydrogen bromide, besides retarding the explosion orcomplete combustion of the starting material, has the eflect ofinhibiting decomposition of the carbon structure of such startingmaterials so that the resulting oxygenated compounds contain at leastthe same number of carbon atoms per molecule as the starting material.

As stated, the halogenated hydrocarbons which may be oxidized inaccordance with the process of the present invention contain a tertiarycarbon atom of aliphatic character and may therefore be representedgenerally by the formula wherein each R represents a like or diflerentalkyl, aryl, alicyclic or aralkyl radical, two of which may be joinedtogether to form an alicyclic ring, and one or more oi which aresubstituted with halogen atoms of atomic No. 9 to 35, i. e. fluorine,chlorine and/or bromine. The preferred class of halogenated hydrocarbonswhich may be used as the starting material comprises chlorinated orbrominated saturated aliphatic hydrocarbons containing at least onetertiary carbon atom and having the halogen atom or atoms attached toone or several carbon atoms of the various alkyl radicals attached tothe tertiary carbon atom, which latter carries a replaceable hydrogenatom. These halogenated hydrocarbons may contain one or more chlorine orbromine atoms or combination of them. The following is a non-limitinglist of representative chlorinated and/or brominated saturated aliphatichydrocarbons containing at least one tertiary carbon atom having ahydrogen atom linked directly thereto which may be oxidized according tothe process of the invention: 1-ch1oro-2-methyl propane (isobutylchloride), 1-bromo-2-methy1 propane (isobutyl bromide), 1,1-dichloro-2-methyl propane, 1,1-dibromo-2-methyl propane, 1-ch1oro-1-bromo-2-methy1propane, 1-chloro-2- chloromethyl propane, l-chloro-Z-bromomethylpropane, 1-chloro-3-methyl butane (isoamyl chloride), 1-chloro-2-methylbutane, 1-bromo-3- methyl butane, 1,2-dichloro-3-methyl butane,1,2-dichloro-2,3-dimethyl butane, 1-bromo-4- methyl pentane, 2chloromethyl 7 1 chloro 3- methyl pentane and the like, together withtheir homologues. The fluorine-containing aliphatic hydrocarbons havinga saturated tertiary hydrocarbon therein are also suitable, althoughless preferred. Among representative examples of this class are suchcompounds as 1-fluoro-2- methyl propane, l-chloro-l-flu0ro-2-methylpropane, 1-fiuoro-3-methyl butane, l-bromo-l-fluoro-3-methyl butane,2-fluoro-3-methyl butane, 1,1-difiuoro-2-methyl propane and the like,together with their homologues. The fluorinecontaining hydrocarbonsreferred to in the present application can be prepared from self-evidentappropriate starting materials by addition 01 hydrogen fluoride tocompounds containing an aliphatic double bond, or by treating thecorresponding chlorinated compound with hydrogen fluoride wherebyfluorine atoms are substituted for chlorine atoms according to thegeneral methods described in Jour. Am. Chem. Soc, vol. 67, pages 1194 to1199. Also, one or more of the aliphatic radicals attached to thetertiary carbon atom may be substituted by alkyl, aralkyl, or alicyclichydrocarbon radicals, one or more of which contains chlorine, bromine,and/or fluorine, reference being made, for example, to such compounds asl-chloro-z-phenyl propane, l-bromo- 2-benzyl propane,1-chloro-2-naphthyl propane, 1-chloro-2-tolyl propane,1-chloro-2-methyl-3- phenyl butane, 2-chloropheny1 propane, l-chloro-2-cyclohexyl propane, 1,1-dichlorophenyl-2,2,2- trichloroethane,1-fiuoro-2-phenyl propane, 1- chloro-l-fluoro-Z-phenyl propane,2-fluoro-3- cyclohexyl butane and the like, as well as their homologues.

Instead of employing individual members of the above-mentioned class ofhalogenated hydrocarbons containing at least one tertiary carbon atom ofaliphatic character, the present process is also applicable, at least insome instances, to the controlled oxidation of mixtures of compounds ofthis class, as well as mixtures containing one or more of the compoundsof the above-defined class, together with one or more other organiccompounds such as hydrocarbons like isobutane, etc. The oxidation ofsuch mixtures, when effected in accordance with the process of thepresent invention, results in the production of mixtures containing thecorresponding peroxides and hydroperoxides.

It was stated above that the slow (i. e. nonexplosive) controlledoxidation of the aboveoutlined class of halogenated hydrocarbons iseffected in accordance with the present invention at temperatures belowthose at which spontaneous combustion or substantial decomposition ofthe carbon structure occurs. This upper temperature limit will, at leastin part, depend on the specific substance treated, as well as on theproportions thereof and of the oxygen and hydrogen bromide present inthe vaporous mixture subjected to the elevated temperatures. Generallyspeaking, this upper temperature limit is in the neighborhood of about200 C. Howevensome of the more stable organ c compounds of the definedclass may be heated together with oxygen and hydrogen bromide to highertemperatures, e. g. about 250 C.

or sometimes even higher, particularly in the presence of inertdiluents, without causing the mixture to decompose with the concurrentformation of high yields of carbon. In this connection it is to be notedthat excessively high tempera tures, even though they may be below theexplosive region, should be avoided because of certain undesirable sidereactions such as excessive conversion of the added hydrogen bromide toform organic bromides. This in itself is not detrimental because theorganic bromides themselves may be treated in accordance with thepresent invention to form halogen-free oxygenated organic compounds andhydrogen bromide (so that in eiIect at least a portion of the hydrogenhalide is regenerated and may be reused). Nevertheless, the excessiveformation of organic bromides, during the controlled oxidation of agiven compound, is undesirable because this decreases the catalystconcentration and therefore may affect the yield or output of thedesired oxygenated product or products. As stated, the upper temperaturelimit is generally in the neighborhood of about 20026. However, withshorter contact periods this temperature may be raised above thementioned limit. Nevertheless, some of the more readily oxidizablecompounds may be economically oxidized according to the present processat lower temperatures, e. g. about 150 C. and lower. With a furtherdecrease in the operating temperature the output of desired product perunit of time will decrease so that at temperatures of below about 100 C.the controlled oxidation in the presence of hydrogen halides, orsubstances capable of yielding them under the operating conditions, maybecome uneconomical.

The reaction may be efiected in the liquid or vapor phase, or in a.two-phase liquid-vapor system. Since it is difiicult to maintain adesirable relatively high oxygen concentration when the reaction isconducted in the liquid phase, it is generally preferable to effect theoxidation according to the present invention in the vapor phase. Sincesome of the relatively higher boiling halogenated hydrocarbonscontaining a tertiary carbon atom of aliphatic character cannot beeffectively maintained in the vapor phase and in contact with suflicientconcentrations of oxygen and of hydrogen bromide without causingspontaneous combustion, the oxidation of such corripounds may be readilyeffected in the presence of inert diluents such as steam, nitrogen,carbon dioxide, and even methane, which latter is relatively stable attemperatures at which the halogenated derivatives may be oxidizedaccording to the invention. Of the above diluents, the use of steam isbelieved to be most advantageous because the hydrogen bromide may thenbe removed from the reaction mixture as an overhead fraction ordistillate in the form of its constant boiling mixture of hydrogenbromide and water.

Although the volumetric ratios of the starting material to the oxygenmay vary within relatively wide limits, it may be stated thatsatisfactory yields of the peroxides and/or hydroperoxides 6 hazards. Onthe other hand, the use oi oxygento-haiogenated hydrocarbon ratiosconsiderably below equivolumetric will lower the output of the desiredorganic peroxides per unit 01' time because of. the presence of lessoxygen per unit of space. This renders the process less economical.ever, the process is still operable and, in fact, it must be noted thata lowering of the oxygen-tohalogenated hydrocarbon ratio may cause amore rapid consumption of oxygen per unit of time.

It was stated above that satisfactory yields of the desiredoxygenated'compounds may be obtained when equivolumetric mixtures ofoxygen and the specified organic starting material containing a tertiarycarbon atom of aliphatic character are subjected to the action ofhydrogen bromide at the operating temperature specified herein. Suchmixtures usually present no hazards as far as explosions are concerned,the hydrogen bromide apparently acting as an explosion retardant orinhibitor.

The invention may be executed in a batch, intermittent or continuousmanner. When operating in a continuous system, all of the reactants aswell as the diluents, if diluents are used, and the catalyst may befirst mixed together, and the mixture may then be conveyed through thewhole length 01' the reaction zone. In the alternative, it is possibleto introduce at least a portion of the catalyst and/or of one or both ofthe reactants, i. e. oxygen and the halogenated hydrocarbon subjected tooxidation, at various intermediate points along the reaction zone. Suchoperation may be frequentlydesirable to control the operating con--ditions in the reaction zone. Generally, the contact time may varywithin relatively. wide limits and is at least in part dependent on theother operating conditions such as specific starting material, theratios thereof to the oxygen and/or the catalyst, the presence orabsence of inert diluents. the operating temperatures and pressures,etc. In a continuous system it has been found that satisfactory yieldsof the desired oxidation products may be obtained with contact periodsof between about .1 and about 3 minutes. Nevertheless, shorter or longercontact times may also be employed, particularly dependent on thespecific material treated and the hydrogen bromide concentration in thereaction mixture.

Instead of using pure or substantially pure oxy-.

gen for the oxidation in accordance with the process of the presentinvention, it is also possible to employ oxygen-containing mixtures,such as air. or even substances capable of yielding molecular oxygenunder the operating conditions.

The following examples will further illustrate various phases of thepresent invention, it being understood that the invention is notrestricted to said examples but is coexclusivein scope with-the appendedclaims.

Example I The reactor consisted of a coil of glass tubing having aninternal diameter of 25 mm. This coil,

vided accurate control oi the reaction temperature.

a temperature of about C. under substantially atmospheric pressure.Measured in'volumes of vapor at normal temperature and pressure (20 C.and 1 atmos.) feed was conveyed into the reactor at the following rates:isobutyl chloride, 2'75 cc. per minute: oxygen, 275 cc. per minute; andhy- How- The feed to the reactor was preheated, mixed and then conveyedthrough the reactor at drogen bromide, 45 cc. per minute. 'From thereactor the reaction products were conveyed through water to separatethe water-soluble compounds from the water-insoluble phase. The latterwas collected and extracted further with water to efl'ect substantiallycomplete removal of watersoluble compounds. This water-extract wascomblned with the first extract and subjected to extraction withtertiary butyl chloride for removal of the chloro-tertiary-butylhydroperoxide. The latter compound was obtained from the tertiary butylchloride by distillation in vacuo.

By recovery and analysis of the reaction products, the material balancegiven below was obtained.

are E a e.

or e qu va en Product M015 Equivalent, Mols Chloro-tertiary-butylhydroperoxide 0. 563 0. 563 0. 663 Isobutylene chlorhydrin 0. 521 0.5210. 260 Haloacetone 0. 0.031 Isobutyric acid. 0. 0.116 Water 0.353Hydrogen halide. Carbon dioxide. 0.018 Carbon monoxide... 0.097 0240.049

0x gen 1.056 1.056 Iso ntyl chloride 1.450 1.450 Isobutylene dibromide0. 070 0.070

Output 2. 796 2. 446 Input 2. 790 2.600 Unaccounted for... .per cent.. 05. 9

From the foregoing material balance, the following conversions andyields were obtained:

Per cent Isobutyl chloride converted 48 Oxygen converted 59 Conversionof isobutyl chloride to chloro-tertiary butyl hydroperoxide Conversionof oxygen to chloro-tertiary-butyl hydroperoxide 22 Yield ofchloro-tertiary-butyl hydroperoxide based on isobutyl chloride 42 Yieldof chloro-tertiary-butyl hydroperoxide based on oxygen 36 When anequivolumetric vaporous mixture of isobutyl chloride is subjected to thesame operating conditions as described above, but in the absence ofadded hydrogen bromide catalyst, no rer action occurs. Only by raisingthe temperature far in excess of that employed with the hydrogen bromidecan oxidation be made to occur and, even then, production of oxygenatedcompou s, ot er than carbon monoxide, carbon dioxide and water, isrelatively small.

Example II ployed to effect catalytic oxidation of isobutyl bromide at atemperature of about 160 C. The

vaporous feed was introduced at the rate of 275 cc. per minute ofisobutyl bromide, 275 cc. per minute 01' oxygen and 50 cc. per minute ofhydrogen bromide. The products were recovered as previously describedexcept that the aqueous water extract was extracted with ether insteadof tertiary butyl chloride in order to recover the bromo-tertiary-butylhydroperoxide. The material balance was as follows:

Ifiobutgl E OxygIcn roml e quiva ent, Pmduc Equivalent, M015Bromo-tertiary-butyl hydroperoxide 0.021 0.021 0.021 Bifomohydrin 0. 2460.246 0. 123 Dibromidcs. 0. 061 0.061 Bromoketone 0. 035 0. 035 0. 018atcr l 0. 444 0. 222 Hydrogen bromide. 0. 062 Oxygen 0. 242 0. 242Isobuty] bromide 0. 292 0. 292

Output 0. 055 0. 202 Input 0. 080 0. 000 Unaccounted for. percent.. 4 9

The monobromo-tertiary-butyl hydroperoxide produced had the structuralformula:

H: and was demonstrated to have been formed in the following manner. Thepresence of peroxidic oxygen was shown by treating a sample wthpotassium iodide acidified with 50% sulfuric acid and. after standingabout 15 minutes under carbon dioxide, titrating the released iodinewith sodium thiosulfate. Another sample of the bromo hydroperoxide wasmixed with an excess of an equimolecular mixture of tertiary butylalcohol and 65% sulfuric acid. After standing for '72 hours attemperatures of 15 C. to 30 C., a second phase which appeared wasremoved. It was a waterinsoluble liquid having a refractive index (20/D)of 1.4448 and the ability to oxidize like other peroxides. Analysisshowed 38.4% bromine compared with 35.6% calculated for the expectedmono-bromo-di-tertiary-butyl peroxide CH: CH:

The oxidation of isobutyl bromide was repeated as described in the aboveexample except that there was used a temperature of about C. and halfthe amount of hydrogen bromide catalyst, namely, 25 cc. per minute. Thematerial balance was as follows:

Igohutgl F Oxygen romi c .quivnlcnt Pmdm Equivalent, Mols Mols IBromo-tcrtiary-butyl hydroperoxide" Gaseous Hydrocarbon (0 11,). Carbondioxide Oxygen 0.183

Output. 0. 523 0. 481 Input 0. 518 0.518 Unaccounted for. .percent. 0 7

In like manner the other hereinbefore outlined halogenated hydrocarbonscontaining a tertiary carbon atom of aliphatic character to which islinked'di-rectly a replaceable hydrogen atom can be oxidized to usefulproducts in the presence of deliberately added hydrogen bromide ascatalyst. When the halogenated hydrocarbon is one having the chlorine orbromine atom linked to the carbon atom directly adjacent to the tertiarycarbon atom, as is the case in isobutyl chloride, the principaloxygenated products will be the corresponding halogenated hydroperoxideand halogenated alcohol. The formation of halogenated hydroperoxidesrather than peroxides appears to be favored by the proximity of thehalogen to the replaceable hydrogen atom linked to the tertiary carbonatom. By using as reactant a compound having the halogen atom or atomsattached to the carbon atom at least once removed from the tertiarycarbon atom, di(halogenated hydrocarbon) peroxides are produced by theprocess. In such compounds the efiect of the halogen atom on the t pe ofoxidation which occurs on the tertiary carbon atom is diminished oreliminated. Thus, such a compound as isoamyl chloride can be subjectedto the process of the invention and there is produced bothchloro-di-tertiary-amyl peroxide and chloro-tertiaryeamyl-hydroperoxide.

Although the amount of added hydrogen bromide employed as catalyst maybe varied over wide limits in the broad concept of the invention, theproportion of hydrogen bromide has an eifect on the nature of theproducts produced when the halogenated compound used as reactant has thehalogen atom attached to a carbon atom one or more carbon atoms removedfrom the tertiary carbon atom. In this connection the use of highconcentrations of hydrobromide tends to favor production of high yieldsof the diperoxides, whereas with relatively lower hydrobromide conmay beadvantageous, particularly for the treatcent, some hydroperoxides willbe formed when Neverusing a material like isoamyl chloride. t-heless, asstated, the increase in the catalyst concentration tends to favor theformation of peroxides containing two organic radicals. attached to theperoxy oxygen atoms.

It was pointed out that the yields of the hydroperoxides can beincreased with certain reactants when the reaction is eflected atsuperatmospheric pressures. However, the process in general may also beefi'ected at atmospheric or even subatmosphericpressures. The use ofsuperatmospheric centrations, other conditions being maintained equal,the reaction mixture contains larger amounts of the hydroperoxides.Generally speaking, when a hydrogen bromide concentration is below about10%, i. e., when such hydrogen bromide comprises less than 10% of thetotal mxture present in the reaction zone, the reaction product formedby such catalytic oxidation in accordance with the process of thepresent invention favors formation of hydroperoxides having the samenumber of carbon atoms permolecule as the starting material, and the useof higher hydrogen bromide concentrations results in the formation ofreaction products containing proportionally greater amounts of thecorresponding di-organic peroxides, i. e. peroxides in which each of theperoxy oxygen atoms is attached to a halogenated radical via a tertiarycarbon atom ofaliphatic character, these peroxides having twice as manycarbon atoms per molecule as the organic material subjected tooxidation. When the volumetric or molal concentration of the hydrogenbromide in the reaction mixture subjected to oxidation is increasedabove about 20%, such an .increase ofv the catalyst concentration doesnot have a marked effect on the percentage of oxygen which will react,or on the yield of the peroxides. Satisfactory yields of the desiredorganic hydroperoxides may be obtained in accordance with the process ofthe presentinvention when the hydrogen halide concentration is below theaforementioned 10%, and preferably between about 4% and 6%. However,higher or lower concentrations of the catalyst may be employed. In fact,the use of lower concentrations, e. g. about 2%,

pressures is preferred not only because it permits the utilization oflower hydrogen bromide catalyst concentrations, but also because more ofthe mixture subjected to treatment may be conveyed.

through a given unit of reaction space per unit of time. v

The halogenated hydroperoxides produced by the process are novelcompounds not heretofore obtainable. Broadly, these compounds arehalogen-substituted hydrocarbon hydroperoxides wherein the hydroperoxyradical (-0011) is linked directly to a saturated tertiary carbon atomand the substituent halogen of atomic No.

9 to 35, of which there may be more than one, is linked directly toother carbon atoms. A- preferred class is the monochloroor monobromoetertiary-alkyl hydroperoxides and the most preferred compounds aremonochloro-tertiary-butyl hydroperoxide and monobromo-tertiary-butylhydroperoxide which could not be produced prior to our invention owingto the peculiar influence of the halogen atom. United States Patent2,223,807 describes the preparation of tertiarybutyl hydroperoxide bydissolving tertiary-butyl alcohol in strong sulfuric acid and thenadding hydrogen peroxide whereby oxidation of the tertiary-butyl alcoholoccurs to give the desired hydroperoxide. alcohol, i. e. isobutylenechlorhydrin, is substituted for tertiary-butyl alcohol and preparationof the hydroperoxide is attempted, it is not successful apparently owingto the peculiar effect of the halogen substituent. By use of the directoxidation method of the present'invention, these novel I hydroperoxidescan now be obtained.

The compounds of the invention can be represented by the formula:

wherein each R. represents-a like or different alkyl, aryl, aralkyl oralicyclic radical, one or more of which contains halogen substitu'entsoi atomic No. 9 to 35. Some representative exam-v ples include suchcompounds as: l-chloro-2- methyl 2 hydroperoxy propane, 1-bromo-2- Itmust be'noted that when monochloro-tertiary-butyl 11 yl-2-hydroperoxybutane, l,1-dichloro-2-methyl- 2-hydroperoxy propane,2-chloro-3-methyl-3- hydroperoxy butane, 1-fluoro-2-methyl-2-hydroperoxypropane, 2-fiuoro-3-methyl-3 hydroperoxy butane,1-chloro-3-methyl-3-hydroperoxy butane,l-fiuoro-1-chloro-2-methy1-2-hydroperoxy propane,1-chloro-4-methyl-4-hydroperoxy hexane,1,1,1-trichloro-2-methyl-2-hydroperoxy propane, 2chloro-2-fiuoro-3-methyl-3-hydroperoxy butane,l-chloro-2-naphthyl-2-hydroper oxy propane, 2-chlorophenyl-2-hydroperoxypropane, 1 chloro-2,3-dimethyl-2,3-dihydroperoxy butane,1-chloro-2-chloromethyl-2-hydroperoxy propane, 1chloro-2-bromomethyl-2-hydroperoxy propane,1-ch1oro-2-phenyl-2-hydroperoxy propane, 1-fiuoro-2-phenyl-2-hydroperoxybutane, l-chloro-2-cyclopentyl-2-hydroperoxy propane, and the like,together with their homologues and further halogen substitution productsof chlorine, bromine and/or fluorine. Preferably the compounds containnot more than six carbon atoms. In general, the lower compounds producedby the process are liquid materials which have some water solubilityalthough the higher products are crystalline solids and are lesssoluble.

The products can be recovered from the reaction mixture by ordinarydistillation procedures, preferably under suitably reduced pressures,since the peroxides and hydroperoxides are characterized by remarkablestability in contrast to peroxides and hydroperoxides not having theperoxy or hydroperoxy groups linked to a tertiary carbon atom and whichare subject to violent explosions upon being heated or subjected toshock. In addition, the lower water-soluble hydroperoxides of theinvention can be recovered by extracting the reaction mixture withwater. This extract may also contain the halogenated alcohol produced.By extracting the water extract again with ethers or halogenatedhydrocarbons, a concentrate of the hydroperoxide can be obtained fromwhich the hydroperoxide is secured by distillation.

The products of the invention are very useful materials in that theirnovel structure in the case of the peroxides and hydroperoxides enablestheir use in preparation of other valuable derivatives. Further, theperoxides and hydroperoxides can be used as polymerization catalysts, asadditives to improve the cetane value of Diesel fuels, and as oxidizingagents such as for treating textile materials.

We claim as our invention:

1. A process for the production of organic halogen-containing peroxideswhich comprises reacting a vaporous mixture comprising oxygen and ahalogen-substituted saturated hydrocarbon in the presence of addedhydrogen bromide at an elevated temperature which is below thespontaneous combustion temperature of the mixture, saidhalogen-substituted hydrocarbon containing a saturated tertiary carbonatom having a hydrogen atom linked directly thereto and containing atleast one substituent halogen of atomic No. 9 to 35, and recovering theperoxide from the reaction mixture thus formed.

2. The process according to claim 1 wherein an inert diluent is employedas a carrier to maintain the reactants in the vapor state.

3. A process for the production of organic halogen-containing peroxideswhich comprises reacting a vaporous mixture containing oxygen and ahalogen-substituted saturated aliphatic hydrocarbon in the presence ofadded hydrogen bromide at a temperature between about 100 C. and thetemperature at which spontaneous combustion of the reaction mixtureoccurs, said halogensubstituted hydrocarbon containin a saturatedtertiary carbon atom having a replaceable hydrogen atom attacheddirectly thereto and containing at least one substituent halogen ofatomic No. 9 to 35, and recovering the peroxide from the reactionmixture thus formed.

4. A process for the production of a monohalogen-substitutedtertiary-butyl hydroperoxide which comprises reacting a vaporous mixturecomprising oxygen and an isobutyl monohaiide in the presence of addedhydrogen bromide at an elevated temperature which is below thespontaneous combustion temperature of the mixture, said isobutylmonohaiide having the halogen atom therein of atomic No. 9 to 35, andrecovering the monohalogen-substituted tertlary-butyl hydroperoxide fromthe reaction mixture.

5. A process for the production of monochlorotertiary-butylhydroperoxide which comprises reacting a vaporous mixture containingoxygen and isobutyl chloride in the presence of a substantial proportionamounting to at least 1% of added hydrogen bromide at a temperaturebetween about C. and the temperature at which spontaneous combustion ofthe mixture occurs, and recovering the monochloro-tertiary-butylhydroperoxide from the reaction mixture thus formed.

6. A process for the production of monobromotertiary-butyl hydroperoxidewhich comprises reacting a vaporous mixture containing oxygen andisobutyl bromide in the presence of a substantial proportion amountingto at least 1% of added hydrogen bromide at a temperature between about100 C. and the temperature at which spontaneous combustion of themixture occurs, and recovering the monobromo-tertiary-butylhydroperoxide from the reaction mixture thus formed.

7. A process for the production or monochlorotertiary-butylhydroperoxide which comprises reacting substantially equivolumetricvaporous amounts of oxygen and isobutyl chloride at substantiallyatmospheric pressure and at a temperature of about C. to 200 C. in thepresence of added hydrogen bromide employed in a substantial volumetricamount up to about one-half that of the isobutyl chloride, extractingthe resulting reaction mixture with water, extracting the resultingextract with tertiary-butyl chloride, and separating themonochloro-tertiary-butyl hydroperoxide from the tertiary-butyl chlorideby distillation.

8. A process for the production of monobromotertiary-butyl hydroperoxidewhich comprises reacting substantially equivolumetric vaporous amountsof oxygen and isobutyl bromide at substantially atmospheric pressure andat a temperature of about 150 C. to 200 C. in the presence of addedhydrogen bromide employed in a substantial volumetric amount up to aboutonehalf that of the isobutyl bromide, extracting the resulting reactionmixture with water, extracting the resulting extract with tertiary-butylchloride, and separating the monobromo-tertiary-butyi hydroperoxide fromthe tertiary-butyl chloride by distillation.

9. In a process for the production of organic peroxides, the steps ofsubjecting vapors of a halogen-substituted saturated hydrocarboncontaining a saturated tertiary carbon atom having a hydrogen atomlinked directly thereto, and containing substituent halogen of atomicNo. 9 to 35, to the action of oxygen in the presence of added hydrogenbromide and effecting the reaction at an elevated temperature which isbelow 13 the spontaneous combustion temperature of the mixture.

10. In a process for the production of Halogenated organic peroxides,the steps of subjecting vapors of an isobutyl monohalide having thehalogen atom of atomic No. 9 to 35 to the action of oxygen in thepresence of added hydrogen bromide and efiecting the reaction at atemperature between about 150 C. and 200 C. under substantiallyatmospheric pressure.

11. A halogen-substituted hydrocarbon hydroperoxide wherein thehydroperoxy radical is linked directly to a saturated tertiary carbonatom, and the substituent halogen has an atomicnumber-oi9to35andislinkeddirectlytocarbon.

12. A halogen-substituted tertiary-alkyl hydroperoxide containing atleast one halogen substltuent of atomic No. 9 to 35.

14 13. A monohalogen-mbstituted tertiary-butyl hydroperoxide wherein thehalogen substituent has an atomic number of 9 to 35.

14. A chloro-tertiary-butyl hydroperoxide. 15. Monochloro-tertiary-butylhydroperoxide. 16. Monobromo-tertiary-butyl hydroperoxide.

WILLIAM E. VAUGHAN. FREDERICK F. RUSI.

REFERENCES CITED The following references are of record in the flie ofthis patent:

UNITED STATES PATENTS 15 Number Name Date 2,395,523 Vaughan et a1 Feb.26. 1946 2,403,771 Vaughan et a1. July 9, 1946 2,403,772 Vaughan et a1.July 9, 1946

